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August 27, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
An amount of 25ml of a 0.8 Molar solution of pure KNO3 and placed in a volumetric flask. Is added water until the thin volume reaches exactly 500ml. which the final concentration?
Thursday, January 21, 2016 by Alan

Chemistry
An experiment being conducted, the pressure is 0.9 atm and the temperature is 18 ° C. One of the steps of experience requires the combustion of 500 ml of ethanol (d = 0.78 g / ml). Whereas the burning this amount of ethanol does not significantly alter the enviroments ...
Thursday, January 21, 2016 by Kennia

Chemistry
On calcination 80g of a marble were obtained 42 g of calcium oxide. The degree of purity of marble?
Thursday, January 21, 2016 by Jessica

Chemistry
how can magnesium chloride be lost in a reaction and how can we ensure that it is pure?
Thursday, January 21, 2016 by Stoof

Chemistry
What happens if we add 200 mg of calcium hydroxide in 100 g of water at 20 ° C?
Thursday, January 21, 2016 by Anna

Chemistry 101
The distance from the Earth to the sun is approximately 9.37 x 10^7 miles. How long does it take for light from the sun, to reach the earth? Speed of light is 3.00 x 10^8 m/s. Use dimensional analysis to solve.
Thursday, January 21, 2016 by Lilly

Chemistry
Calculate the equilibrium constant for the equilibrium knowing that there are 2 moles of O2 H2, 6 moles of O2 and 3 moles of H2O in a jar reactor 2L? 2 H2 + O2 = 2 H2O
Thursday, January 21, 2016 by Bill

Chemistry
An aluminum sheet used for food preservation weighs about 0.05 g/cm-2 How many electrons are in a 1 cm2 of this sheet?
Thursday, January 21, 2016 by Alan

Chemistry
Calculate the total mass of aluminum, with 90% purity, required to produce 448g of iron in the process Fe2O3 + 2 Al = Al2O3 + 2 Fe
Thursday, January 21, 2016 by Cindy

Chemistry
Consider the decomposition reaction of the following represented hydrogen peroxide: 2 H2O2 (aq) = 2 H2O + O2 In the experiment, the average speed of this reaction given time interval was 16 mol • s-¹ in relation to hydrogen peroxide. What is the average speed ...
Thursday, January 21, 2016 by Victoria

chemisty
Gary is carrying out two chemistry experiments. In experiment A he mixes hydrochloric acid with sodium carbonate. In experiment B he mixes nitric acid with copper carbonate. Explain what Gary will need to do in order to test the gas produced in each experiment. I don't ...
Thursday, January 21, 2016 by lala

Chemistry
1.How Many Grams Of Sulphur Contains The Same Number Of Moles As 4.6g Of Sodium? 2.Calculate The Number Of Moles In 28.6g Of Na2CO3.10H2O?
Thursday, January 21, 2016 by Saich

Chemistry
Ln(P2/p1)=ln(-delta Hvap/R)•(1/T1-1/t2) I have ammonia at normal boil with a temp at 39.2C find the Hvap
Thursday, January 21, 2016 by Anonymous

chemistry
how many ml of 6M HCl solution are required to bring the pH of 10 ml of a 4M NaOH solution to 2.0
Thursday, January 21, 2016 by Razakou Maman

chemistry
calculate the weight in grams far a given solution of sodium thiosulphate crystals of strength 2.0M
Thursday, January 21, 2016 by sonia

maths
in a class of 35 students twice as many study chemistry and study physics half a many study chemistry as study both subjects illustrate it on a venn diagram
Thursday, January 21, 2016 by owusu afriyie

chemistry
how to draw bicyclo 3.1.1 heptane ? I need steps to draw any of this compounds in exam ?
Thursday, January 21, 2016 by ahmed

Chemistry
1) 0.19 litre of an ideal monatomic gas (Cv,m = 3R/2) initially at 83 °C and 47 atm pressure undergo an expansion against a constant external pressure of 1.19 atm, and do 2.3 kJ of work. The final pressure of the gas is 1.19 atm. Calculate the change in enthalpy, ΔH 2...
Thursday, January 21, 2016 by Ashley

Chemistry
If a rate of 80.0 mL of an aqueous solution of potassium hydroxide concentration of 0.25 mol / L are partially neutralized by 20.0 mL of an aqueous solution of nitric acid concentration of 0.50 mol L. Determine pH of the final solution. kOH + HNO3 -> H2O + KNO3
Wednesday, January 20, 2016 by Mara

Chemistry
Which one between N2O4 and NO2 is more susceptible to decompose immediately? And why?
Wednesday, January 20, 2016 by Maude

Chemistry
What volume of air at 1.0 atm and 25 degree Celsius must be taken to an engine to burn 1 gallon of gasoline? Assuming that: 2 C8H18 + 25 O2 --> 16 CO2 + 18 H2O provides reasonable model of the actual combustion process. ( The partial pressure of oxygen in air is 0.21 atm ...
Wednesday, January 20, 2016 by Emma

Chemistry
How many grams of aluminum sulfate are produced if 15.7 g Al reacts with excess CuSO4?
Wednesday, January 20, 2016 by karen

Chemistry
What volume of air at 1.0 atm and 25 degree Celsius must be taken to an engine to burn 1 gallon of gasoline? Assuming that: 2 C8H18 + 25 O2 --> 16 CO2 + 18 H2O provides reasonable model of the actual combustion process. ( The partial pressure of oxygen in air is 0.21 atm ...
Wednesday, January 20, 2016 by Emma

Chemistry
The solidified carbon dioxide, dry ice, is used as the refrigerant to temperatures of 78 °C order What physical state of carbon dioxide at 25°C and 1 atm?
Wednesday, January 20, 2016 by Gary

Chemistry
how many L of O2 are needed to react completely with 63.0 L of H2S and STP?
Wednesday, January 20, 2016 by Lori

Chemistry
Consider the chemical reaction below equated   2N2O5 (g) -> 4NO2 (g) + O2 (g) knowing that a certain period of time, N2O5 consumption rate is 0.10 mole / s, determine for the same time interval: a) the average rate of formation of NO2 b) the average speed O2 formation
Wednesday, January 20, 2016 by Selena

Chemistry
A concentration of PCL5(g),4,0 mol/L, verifies that the process PCl5(g) = PCl3(g) + Cl2(g) is achieved with a degree of balance of 20% Calculate the equilibrium of the reaction constant
Wednesday, January 20, 2016 by Kelly

Spanish
Dr. Mario Jose Molina won the Nobel Prize in Chemistry for his work studying which problem? a. the ozone layer*** b. deforestation c. the El Nino effect d. the greenhouse effect
Wednesday, January 20, 2016 by Kaai97

Chemistry -Dr. Bob
Reacting 1 L of H2(g) with 1 L C2H2(g) (both at STP) results in the formation of 1 L of C2H4(g) if the reaction is maintained at the same conditions (STP) and goes to completion. If this reaction produced 6.3 kJ of heat (absorbed by the surroundings), calculate: a) the PV work...
Wednesday, January 20, 2016 by Sanaya

Chemistry 101
A crown is determine to weigh 2.65 kg. When this crown is submerged in a full basin of water, the overflow is found to be 145 mL. Is the crown pure gold or a gold-silver alloy? The density of silver is 10.5 g/mL and gold that of gold is 19.3 g/mL. Show work.
Wednesday, January 20, 2016 by Lilly

Chemistry-Dr. Bob
Reacting 1 L of H2(g) with 1 L C2H2(g) (both at STP) results in the formation of 1 L of C2H4(g) if the reaction is maintained at the same conditions (STP) and goes to completion. If this reaction produced 6.3 kJ of heat (absorbed by the surroundings), calculate: a) the PV work...
Wednesday, January 20, 2016 by Sanaya

Chemistry- Dr.Bob
1. Oxygen (O2) is about 20% of our air, with about 80% nitrogen and a bunch of minor components. In Colorado Springs, where I grew up, the elevation is ~ 6500 feet and atmospheric pressure is only around 12 psi (vs. 14.7 psi at sea level). Under those conditions and assuming T...
Wednesday, January 20, 2016 by Sanaya

Chemistry 105
How do I write 23 grams+ 0.022 grams into a significant figure?
Wednesday, January 20, 2016 by Michelle

Chemistry
Is it possible to separate Bi, Cu and Ag from a mixture containing: c(BiO+)=0,08M c(Cu2+)=0,242M c(Ag)=0,106M c(HClO4)=1M Eo Bi = 0,32 V, Eo Cu = 0,337 V, Eo = 0,792 V _______________ Using Nernst equation (E=E°-0,0592/n -logQ) i see it's possible to separate Ag, but ...
Wednesday, January 20, 2016 by Anna

Chemistry
Calculate the concentration of H+ ions of an aqueous solution of nitrous acid ( HNO2) to 0.02 mol/L knowing that the degree of ionization of acid is 3%
Wednesday, January 20, 2016 by Maria

Chemistry
A concentration of PCl5(g), 4,0 mol/L, it appears that the proceeding PCl5(g) => PCl3(g) + Cl2(g) is achieved with a degree of balance of 20%. In these conditions, calculate the value of chemical equilibrium
Wednesday, January 20, 2016 by Matt

Chemistry
Cu+HNO3-Cu(NO3)2+NO+H2O
Wednesday, January 20, 2016 by Dipesh chandak

chemistry
If the vapor pressure of a liquid is 0.850 atm at 20°C and 0.897 atm at 25°C, what is the normal boiling point of the liquid?
Wednesday, January 20, 2016 by Elisha

Chemistry
Hi, we have done an experiment in class where we have an equalibrium between (Co(H2O)6)^+2 + 4Cl^- <-> (CoCl4)^-2 + 6H2O where we added HCl dropwise until a colour change occured which changed the solution into a dark blue as the concentration of the Cholride ions ...
Wednesday, January 20, 2016 by Ivan

Chemistry- Dr.Bob!
1. Oxygen (O2) is about 20% of our air, with about 80% nitrogen and a bunch of minor components. In Colorado Springs, where I grew up, the elevation is ~ 6500 feet and atmospheric pressure is only around 12 psi (vs. 14.7 psi at sea level). Under those conditions and assuming T...
Wednesday, January 20, 2016 by Sanaya

Chemistry
When iron reacts with copper (2) chloride, one of two possible reactions take place: Fe(s) + CuCl2(aq) to FeCl2(aq)+Cu(s) OR 2Fe(s) + 3Cucl2(aq) to 2FeCl3(aq) + 3Cu(s)... What charge does the iron atom have carry in each of the two possible products FeCl2 vs. FeCl3.
Tuesday, January 19, 2016 by Kelly

Chemistry
I don't understand where to start first. Can you break it down for me? Ascorbic acid, also known as vitamin C, has a percentage composition of 40.9% C, 4.58% H, and 54.5% O. The molar mass of ascorbic acid is 176.1 g/mol. Determine the empirical and molecular formulas
Tuesday, January 19, 2016 by GABS

CHEMISTRY
The molar mass of benzene, an important industrial solvent, is 78.0 g/mol and its empirical formula is CH. What is the molecular formula for benzene?
Tuesday, January 19, 2016 by GABS

CHEMISTRY A
an unknown compound contains 85.64% carbon with the remainder hydrogen. It has a molar mass of 42.08 g/mol. Find its empirical and molecular formulas.
Tuesday, January 19, 2016 by GABS

Chemistry
Calculate the equilibrium concentrations of N2, H2, and NH3 present when a mixture that was initially 0.10M N2, 0.10 M H2, and 0.10 M NH3 comes to equilibrium at 500 degrees C. N2(g) + 3H2(g) <--> 2NH3(g) Kc = 0.040 (at 500 degrees C) I'm getting confused with the math.
Tuesday, January 19, 2016 by Anonymous

Chemistry
How many grams of aluminum oxide can be formed by the reaction of 41.2 g of aluminum with oxygen?
Tuesday, January 19, 2016 by Cassidy

Chemistry 101
Solumedrol 1.5 mg per KG of body weight is ordered for a child weighing 2.0 pounds. Solumedrol is available as 75 mg / mL solution. How many mL should the nurse administer? Use dimensional analysis..
Tuesday, January 19, 2016 by Lilly

Chemistry
if i added (0.1N) 4.6 ml of NaOH to 10 ml of Ch3cooh calculate the ph
Tuesday, January 19, 2016 by Zahraa

Chemistry
A 10.0g sample of H2O(l) at 23.0degrees C absorbs 209 joules of heat. What is the final temp of the H2O(l) sample?
Tuesday, January 19, 2016 by Sabrina

Chemistry
The molarity of concentrated HCl purchased for laboratory use is approximately 12.1 M. How many milliliters of this reagent should be diluted to 1.000 L to make 0.100 M HCl?
Tuesday, January 19, 2016 by Kevin

Chemistry 101
Calculate the mass of a cylindrical cork of diameter 1.00 inches and length 2.50 inches. Pay attention to significant figures, Cork density 0.26 g/ mL
Tuesday, January 19, 2016 by Lilly

Chemistry 101
What is the mass of water (in grams and pounds). contained in a 100. foot long pipe that has an internal diameter of 6.5 centimeters? The density of water is 1.00 g/ cm^3. The volume of a cylinder is (pi)r^2L.
Tuesday, January 19, 2016 by Lilly

Chemistry 101
The distance from the Earth to the sun is approximately 9.37 x 10^7 miles. How long does ti take for light from the sun to reach the earth? Speed of light is 3.00 x 10^8 m/s. Show work.
Tuesday, January 19, 2016 by Lilly

Chemistry
The petrol, can be represented by the formula of the octane rating, has earth specifies 704 g/L. Estimate the enthalpy variation when burning 28.5 liters of petrol, assuming energies of connection 0 = 0 (117 kcal) C = 0 (173 kcal) 0–H (111 kcal) C–C (83 kcal) C–...
Tuesday, January 19, 2016 by Anitta

Chemistry
A chemistry laboratory of an experience is being conducted. The pressure is 0.9 atm and the temperature is 18°C. One of the steps of the experience requires the combustion of 500 mL ethanol (Density=0.78 g/mL). Whereas the burning of this amount of ethanol does not ...
Tuesday, January 19, 2016 by Marley

Chemistry
Which THE PH VALUE OF A solution 0,01 mol/l a monoacido that presents ka= 1×10-6
Tuesday, January 19, 2016 by Angelica

Chemistry
What is the minimum percentage of gas (C2H2) formed when 2.66g of calcium carbide (CaC2) reacts completely with 50g water? CaC2+2H2O -> C2H2+ Ca(OH)2
Tuesday, January 19, 2016 by Lany

chemistry
if i have a 21% solution of a product, and i need to make it a 9% solution of the same product what do i do? i am trying to dilute a product that is 21% to a 9% soultion so it can safety be used on cats. i know what to dilute it with, but i do not know how much or the math to ...
Tuesday, January 19, 2016 by michele

chemistry
an average adult inhales a volume of 0.50 liter of air into the lungs with each breath.If the air is warmed from room temperature (20 degree celsius) to body temperature (37 degree celsius),what is the volume of air exhaled?
Tuesday, January 19, 2016 by MHECY

Physical Chemistry
Calculate the work, w, (in J) when 0.6 litre of an ideal gas at an initial pressure of 91.5 atm is expanded isothermally to a final pressure of 2.15 atm against a constant external pressure of 2.15 atm. I got -130.71 J, but apparently it is wrong. Help is greatly appreciated. ...
Monday, January 18, 2016 by Cole

Chemistry
Would there be any effect on the amount of precipitate in the experiment if tap water containing calcium ions is used instead of deionized water to dissolve the reactants. Assume that Na2CO3 is present in the excess.
Monday, January 18, 2016 by Hannah

chemistry
If you put 0.25 molar solution of Sodium Chloride (NaCl) in 100 ml of distilled water. ... how much salty precipitate remains in an evaporating dish from 10 ml of solution?
Monday, January 18, 2016 by Bev

Chemistry
Why is the pressure of a gas does not depend on the molar mass of the gas?
Monday, January 18, 2016 by Sanaya

Chemistry 101
Joe Smith, the chemical engineer from Acme Chemical Company, wanted to determine the final volume in a large glass cylinder is he dropped a 12.52 pound ingot of lead whose density was 11.3 g/cm^3 into the cylinder which already contained 2500. mL of water. What is the final ...
Monday, January 18, 2016 by Lilly

chemistry
The titration of 5.40 mL of a saturated solution of sodium oxalate, Na2C2O4, at 25∘C requires 29.4 mL of 2.200×10−2 M KMnO4 in acidic solution. What mass of Na2C2O4 in grams would be present in 1.00L of this saturated solution?
Monday, January 18, 2016 by sara

Chemistry
Calculate the average kinetic energy of 1 mol of hydrogen molecules and of 1 mol of sulfur hexafluoride molecules at 25 degrees Celsius.
Monday, January 18, 2016 by Sanaya

Chemistry 101
Joe Smith, the chemical engineer from Acme Chemical Company, wanted to determine the final volume in a large glass cylinder is he dropped a 12.52 pound ingot of lead whose density was 112.3 g/cm^3 into the cylinder which already contained 2500. mL of water. What is the final ...
Monday, January 18, 2016 by Lilly

Chemistry
Calculate the average kinetic energy of 1 mol of hydrogen molecules and of 1 mol of sulfur hexafluoride molecules at 25 degrees Celsius.
Monday, January 18, 2016 by Lana

Chemistry 101
What is the mass of water (in grams and pounds). contained in a 100. foot long pipe that has an internal diameter of 6.5 centimeters? The density of water is 1.00 g/ cm^3. The volume of a cylinder is (pi)r^2L.
Monday, January 18, 2016 by Lilly

Chemistry 101
A carpenter is building a deck and needs 750 board meters of ACC chemically treated lumber. The individual boards com in 8 foot and 12 foot lengths. How many boards will he need to complete the deck? If the boards retail at Home Depot for $1.25 per board foot, how much will he...
Monday, January 18, 2016 by Lilly

Chemistry 101
A crown is determine to weigh 2.65 kg. When this crown is submerged in a full basin of water, the overflow is found to be 145 mL. Is the crown pure gold or a gold-silver alloy? The density of silver is 10.5 g/mL and gold that of gold is 19.3 g/mL
Monday, January 18, 2016 by Lilly

chemistry 110
Calculate the volume of 0.300M HNO3 needed to complete neutralize 25.0ml of 0.250M Sr(OH)2
Monday, January 18, 2016 by Doleen

Chemistry
a metal y forms two oxidf u and v.0.75g of u and v contain 0.18g and 0.27g of oxygen respectively.calculate the masses of metals in grams.calculate the masses of metals of metals that combine with gram of oxgen in each case
Monday, January 18, 2016 by Anonymous

chemistry
if 8.99g of scandium and 8.99g of oxgen react to give scandium oxide and a leftover 3.56g.what percentage of scandium oxide is the oxygen
Monday, January 18, 2016 by Anonymous

chemistry
the length of an aluminium bar of length 80cm increases by 1mm on heating.what is the final temperature of the bar if it was initially at temp 20 degree celsius? coeff. of linear expansion of aluminium=25
Monday, January 18, 2016 by Anonymous

Chemistry
If a solution has a large Kb value, will it have a high pH?
Sunday, January 17, 2016 by Alex

organic chemistry
0.68g of a solid diprotic acid was dissolved in 30.0mL of a 0.50 NaOH sol'n. the resulting mixture was then back-titrated against 0.20 M HCl; 25mL were required. Calculate the molar mass of the acid. This acid is a solid salt of a triprotic acid, identify this acidic salt.
Sunday, January 17, 2016 by Jane

chemistry
describe what happen when a piece of wet red litmus paper is passed through a hydrogen gas.
Sunday, January 17, 2016 by sarah

Chemistry 101
A 16 Gauge wire has a diameter of 0.0508 inch. Calculate the length in meters of a 5.00 pound spool of this wire. The density of copper is 8.92g cm^-3
Sunday, January 17, 2016 by Scott L

Chemistry 101
Which o^ these possesses more mass, a sphere of Mecury (Hg) with a diameter of 2.00 cm or a cube of lead (Pb) measuring 2.00 cm on each side? Volume of a sphere = 4/3(pie)r^3.
Sunday, January 17, 2016 by Scott L

chemistry
describe what happen when a piece of wet red litmus paper is passed through a hydrogen gas.
Sunday, January 17, 2016 by sarah

Chemistry
Calculate the equilibrium concentrations of N2, H2, and NH3 present when a mixture that was initially 0.10M N2, 0.10M H2, and 0.10M NH3 comes to equilibrium at 500 degrees C. N2(g) + 3H2(g) equilibrium arrows 2NH3(g) Kc = 0.040 (at 500 degrees C)
Sunday, January 17, 2016 by Anonymous

Chemistry
At pH 9 what will the ratio of ammonium to ammonia be? The pKa of ammonium is 9.24?
Sunday, January 17, 2016 by Sarah

chemistry help plz
A potassium permanganate solution containing 1.58g of KMnO4 per liter is added into 5 ml of an acidified iron (||) sulfate solution. Decolorizing of KMnO4 solution has been added .Calculate the mass of FeSo4.7H2O which has been dissolved in one liter of solution.
Sunday, January 17, 2016 by cynthia

chemistry
A certain mass of gas occupied 450cm cube at 25°c.At what temperature will it have it's volume reduced half
Sunday, January 17, 2016 by violet

chemistry help
A solution of thiosulfate ions has been prepared by dissolving 4.5g of Na2S2O3.5H2O in 250 ml of solution. Calculate the concentration of the thiosulfate ions S2O3^2- in the solution
Sunday, January 17, 2016 by vicky

chemistry
A potassium permanganate solution containing 1.58 g of KMnO4 per liter is added into 5 ml of an acidified iron (||) sulfate solution .Decolorizing of KMnO4 solution ceases when 10ml of the solution has been added. Calculate the mass of FeSo4.7H2O which has been dissolved in ...
Sunday, January 17, 2016 by angy

chemistry
Tell me plz how we can characterize the compound K3[Al(c2o4)3]?
Sunday, January 17, 2016 by Sana Arshad

Chemistry Really Confused!!
'm confused on how to set up the problem for each question.. 1.) Calculate the empirical formula of a compound if a 6.21 g sample contains 1.67g of cerium and the remainder iodine 2.) An unknown compound contains 85.64% carbon with the remainder hydrogen. It has a molar ...
Saturday, January 16, 2016 by Lina

Chemistry
I'm confused on how to set up the problem for each question.. 1.) Calculate the empirical formula of a compound if a 6.21 g sample contains 1.67g of cerium and the remainder iodine 2.) An unknown compound contains 85.64% carbon with the remainder hydrogen. It has a molar ...
Saturday, January 16, 2016 by Lina

Chemistry
The empirical formula of an oxide of nitrogen containg 30.4 per cent of nitrogen is NO
Saturday, January 16, 2016 by Princess

Chemistry
sample of alumium has a mass 6.3g.calculate the number of mole of alumium present and the number of atom of alumium in the sample(AL=27
Saturday, January 16, 2016 by Hassan

Chemistry
Which of the following compounds contains both ionic and covalent bonds? SiO2 LiCN LiI PCl3
Friday, January 15, 2016 by Jordan

Chemistry
Aqueous hydrobromic acid will react with solid sodium hydroxide to produce aqueous sodium bromide and liquid water. Suppose 61. g of hydrobromic acid is mixed with 41.1 g of sodium hydroxide. Calculate the maximum mass of water that could be produced by the chemical reaction
Friday, January 15, 2016 by Ryan

Chemistry 101
A rectangular prism has these dimensions and mass: Length = 12.6cm, width = 1.256 feet, and thickness = 456 mm. Its mass is 1.2347 pounds. Determine its density in g/cm3.
Friday, January 15, 2016 by mike

Chemistry
hellop
Friday, January 15, 2016 by mike

chemistry
which of the following has highest binding energy (nuclear chemistry) Fe-56 , O-16 , H-3 , U-235 and explain why
Friday, January 15, 2016 by ahmed

Chemistry
When 46.0 ml of 0.18 M HNO3 and 58.0 ml of 0.23 M LiOH are mixed, the concentration of [OH-] after mixing is ?
Friday, January 15, 2016 by Has

Chemistry
When its brakes are applied, a car moving at 10 m/s undergoes an acceleration of -1.2 m/s2. How far does the car travel before it comes to a stop?
Friday, January 15, 2016 by Autumn

Chemistry
In a closed container 1L of chlorine reacts with 1L of nitrogen and 1L of hydrogen. I need to give lewis structure, vsepr, box notation for valence electrons etc. (i know how to do this) But I'm doubting on what the reaction equation would be.
Friday, January 15, 2016 by Nicolas

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